1. Field of the Invention
The present invention relates to a magnetic retriever, more particularly to a telescopic shaft magnetic retriever which is convenient to operate.
2. Description of the Related Art
When screws, nuts, tools or other parts are dropped into inaccessible places, a retriever that is provided with a magnet is used to pick them up. Moreover, a magnetic retriever having a built-in lighting device is particularly useful to retrieve things in the dark.
U.S. Pat. No. 5,384,319 discloses a telescopic shaft magnetic retriever (R) (see FIG. 1), which includes a telescopic shaft 1 having a battery holder 3 at a tip thereof to hold an insulative socket 3a and a set of dry battery cells 4 within the insulative socket 3a. A conductive lamp holder 5 is fastened to the battery holder 3 to hold a lamp 6. A spring 7 is mounted inside the lamp holder 5 and presses against the negative pole of the dry battery cells 4. The lamp 6 has a first contact 6a which is connected to the spring 7, and a second contact 6b which is isolated from the spring 7 while in contact with the conductive lamp holder 5. A transparent tube 8 is fastened to the lamp holder 5 to allow passage of light emitted from the lamp 6 and to hold a magnet 9 for retrieving screws, nuts, tools and other steel parts from inaccessible places. The retriever (R) further includes a control rod 2 which is received in a longitudinal passage inside the telescopic shaft 1 and the conductive battery holder 3. When the telescopic shaft 1 is collapsed, the dry battery cells 4 are pushed away from the bottom of the battery holder 3 by the control rod 2 to compress the spring 7. Therefore, the battery holder 3 is insulated from the positive pole of the battery cells 4 and the circuit is opened. At this time, the lamp 6 is deactivated. When the telescopic shaft 1 is extended out for retrieving things, the control rod 2 is released from the battery cells 4, so that the spring 7 pushes the battery cells 4 backwards to contact the bottom of the battery holder 3, thereby turning on the lamp 6. Through the extension of the telescopic shaft, the lamp 6 is activated to generate light by means of the action of the control rod 2 and the spring 7.
The conventional retriever with telescopic shaft is convenient to bring along. However, the operations of the retriever for turning the lamp on and off involve extending and collapsing the telescopic shaft. It is desirable if the lamp is switchable without extending or collapsing the telescopic shaft.